The present invention relates to a method of elimination from a gaseous or liquid fluid at least one metal or metal compound chosen from the group constituted by mercury and arsenic, by bringing the said fluid into contact with a mercury and/or arsenic recovery mass. The said solid mercury and/or arsenic recovery mass contains a solid mineral dispersant or support, copper and sulphur combined at least partly in the form of copper sulphide and in particular for example in the form of at least one Cu.sub.x S.sub.y sulphide (in which x and y are each a whole number from 1 to 10).
The solid masses of the present invention may be variously called absorption, recovery, extraction or trapping masses.
The patent U.S. Pat. No. 4,094,777 describes a method of producing a mercury recovery mass comprising the incorporation of a copper compound into a mineral support followed by sulphuration at a temperature below 300.degree. C.
Sulphuration according to the method described in this patent is carried out by means of a gaseous agent, for example hydrogen sulphide, or a solution of a mineral sulphide in water or in an organic solvent, for example an aqueous solution of
According to patent application EP-A-107582, a mercury recovery mass is prepared by impregnation of a carrier by means of an organic solution of elementary sulphur or an aqueous solution of a sulphur compound which is decomposable into elementary sulphur at a temperature below 150.degree. C.
After drying and volatilisation of the organic compound or after the aforesaid decomposition, a carrier or support is obtained with a dispersion of non-molten sulphur in the free state.
U.S. Pat. No. 4,474,896 described a mercury recovery mass obtained by bringing into contact a carrier impregnated with a metallic cation capable of forming an insoluble polysulphide, with a mixture of polysulphide and sulphide.